1. Field of the Invention
The present invention relates to technology for printing by forming dots on a printing medium while performing a main scan, and specifically relates to technology for printing images for which there are two types of areas, color areas and monochromatic areas, in the sub-scan direction.
2. Description of the Related Art
In recent years, as computer output devices, there has been a broad popularization of color printers of the type that eject several colors of ink from a head. Among this type of color printer, there are printers that print an image by forming dots on a printing medium by ejecting ink drops from a nozzle while performing a main scan.
Also, there are printing devices that are equipped with a higher number of nozzles that eject only black ink than those for other colored inks. For that kind of printing device, when printing color data, color printing is done using the same number of nozzles for each color. Only the same number of nozzles as the number of nozzles for each color is used for the black nozzles. Then, when printing data that is monochromatic only, the monochromatic printing is performed at high speed using all of the black nozzles.
However, with the printing device noted above, when within the printed image there are two types of areas, monochromatic areas that use only black ink, and color areas, there is the problem that printing cannot be performed efficiently.
Accordingly, an object of the present invention is to efficiently print images for which two types of areas, color areas and monochromatic areas, exist in the sub-scan direction.
To attain at least part of the above and other related objects of the present invention, there is provided a printing apparatus that prints images in a monochromatic area on a printing medium with an achromatic ink alone, and in a color area with chromatic inks, by ejecting ink drops from a nozzle to deposit the ink drops on the printing medium to form dots.
This printing apparatus comprises a printing head having a plurality of single chromatic nozzle groups and an achromatic nozzle group, a main scan drive unit that moves at least one of the printing head and the printing medium to perform main scanning, a sub-scan drive unit that moves at least one of the printing head and the printing medium in a direction that intersects a main scanning direction to perform sub-scanning, and a control unit that controls each of these units (the printing head, the main scan drive unit and the sub-scan drive unit). Each of the plurality of single chromatic nozzle groups consists of plurality of nozzles that are arranged at nozzle pitch kxc3x97D where k is an integer of at least 2 and D is a pitch of main scan lines. The plurality of single chromatic nozzle groups are configured to eject mutually different chromatic inks. The achromatic nozzle group for ejecting achromatic ink consists of a greater number of nozzles that are arranged at nozzle pitch kxc3x97D than each of the single chromatic nozzle groups.
It is preferable that the plurality of single chromatic nozzle groups each consists of mutually equal numbers of nozzles. It is also preferable that the specific achromatic nozzle group includes a same number of nozzles as each of the single chromatic nozzle groups.
In that apparatus, monochromatic mode printing is also executed by repeating a unit scan operation using all the nozzles of the achromatic nozzle group but without using the single chromatic nozzle groups. The unit scan operation consists of k main scans and (kxe2x88x921) sub-scans of a first feed amount. The unit scan operation in the monochromatic mode printing may be performed such that all dot positions in an achromatic unit band consisting of plural main scan lines without any gap therebetween are serviced by the achromatic nozzle group. A monochromatic mode sub-scan of a second feed amount is performed in each interval between each unit scan operations.
In that apparatus, color mode printing is executed by repeating the unit scan operation using a specific achromatic nozzle group and the plurality of single chromatic nozzle groups while a color mode sub-scan of a third feed amount less than the second feed amount is performed in each interval between each unit scan operations. The specific achromatic nozzle group is part of the achromatic nozzle group.
In specific case in the monochromatic mode printing, specific process is executed. The case is when a lowermost main scan line of a second achromatic unit band comes to be positioned within the color area when it is assumed that a set of the color mode sub-scan and the unit scan operation is performed J times (where J is an integer of two or greater). The second achromatic unit band consists of plural main scan lines without any gap therebetween for which the specific achromatic nozzle group services with a single unit scan operation.
In above specific case, a sub-scan whose feed amount is equal to a sum of (Jxe2x88x921) times the third feed amount and (Jxe2x88x922) times a total feed amount of sub-scans performed in one unit scan operation is performed. The printing process proceeds to the color mode printing. Such an embodiment makes it possible to efficiently execute monochromatic printing when an attempt is made to transition to color mode printing.
It should be preferred that the printing process proceeds to the color mode printing, in a case that a lowermost main scan line of the first achromatic unit band comes to be positioned within the color area when it is assumed that the monochromatic mode sub-scan of the second feed amount and the unit scan operation are performed. Such an embodiment makes it possible, based on simple decision criteria, to execute the transition process from monochromatic mode printing to color mode printing.
The printing mode transitioning procedure may be as follows. The case the specific procedure to be performed may include three conditions all to be qualified. (i) A lowermost main scan line of the first achromatic unit band comes to be positioned within the color area when it is assumed that the monochromatic mode sub-scan and the unit scan operation are performed next. (ii) A lowermost main scan line of a second achromatic unit band comes to be positioned within the color area when it is assumed that a set of the color mode sub-scan and the unit scan operation is performed J times (where J is an integer of two or greater). (iii) A lowermost main scan line of the second achromatic unit band comes to be positioned within the monochromatic area when it is assumed that the set of the color mode sub-scan and the unit scan operation is performed (Jxe2x88x921) times. The second achromatic unit band consists of plural main scan lines without any gap therebetween for which the specific achromatic nozzle group services with a single unit scan operation.
If above conditions are all fulfilled, then a sub-scan whose feed amount is equal to a sum of (Jxe2x88x921) times the third feed amount and (Jxe2x88x922) times a total feed amount of sub-scans performed in one unit scan operation is performed; The unit scan operation is performed once, while forming dots in the monochromatic area using the achromatic nozzle group; The printing procedure proceeds to the color mode printing. Such an embodiment also makes it possible to efficiently execute monochromatic printing when an attempt is made to transition to color mode printing.
It is preferable that the printing procedure proceeds to the color mode printing in a case that a lowermost main scan line of the second achromatic unit band comes to be positioned within the color area when it is assumed that the color mode sub-scan and the unit scan operation are performed next. Such an embodiment makes it possible to efficiently transition from monochromatic mode printing to color mode printing when the distance from the lower tip of the print head to the color area and boundary is smaller than a prescribed value.
In a case that main scan line count Lr1 of a remaining monochromatic area is (i) smaller than main scan line count L1 of the first achromatic unit band, (ii) equal to or larger than main scan line count of (Jxe2x88x921) times of main scan line count L2, and (iii) smaller than main scan line count of J times of main scan line count L2, it is preferable the procedure as follows to be performed. A sub-scan whose feed amount is equal to a sum of (Jxe2x88x921) times the third feed amount and (Jxe2x88x922) times a total feed amount of sub-scans performed in one unit scan operation is performed; The unit scan operation is performed once, while forming dots in the monochromatic area using the achromatic nozzle group; and The printing procedure proceeds to the color mode printing. The main scan line count L2 is a main scan line count of a second achromatic unit band. The second achromatic unit band consists of plural main scan lines without any gap therebetween for which the specific achromatic nozzle group services with a single unit scan operation. Such an embodiment makes it possible, based on simple decision criteria, to execute the transition process from monochromatic mode printing to color mode printing.
In a case that main scan line count Lr1 of the remaining monochromatic area is smaller than main scan line count L2, the printing procedure preferably proceeds to the color mode printing. Such an embodiment makes it possible to execute the shifting process from monochromatic mode printing to color mode printing, based on simple decision criteria, when the distance from the bottom edge of the printing head to the border of the color area is smaller than a prescribed value, while recording dots in the monochromatic area and after the main scan has finished.
If (i) the plurality of single chromatic nozzle groups includes C nozzle rows, where C is an integer of at least 2, (ii) each of single chromatic nozzle group includes N nozzles, where N is an integer of at least 2, arranged in the sub-scan direction at the nozzle pitch kxc3x97D and also (iii) the achromatic nozzle group includes a nozzle row consisting of Nxc3x97C nozzles arranged in the sub-scan direction at the nozzle pitch kxc3x97D, then it is preferable that the first feed amount is equal to D, the second feed amount is equal to Nxc3x97Cxc3x97kxc3x97D, and the third feed amount is equal to Nxc3x97kxc3x97D. If such an embodiment is used, the main scan lines recorded by the unit scan operation will touch each other. This makes it easy to execute the transition process between the modes of color mode printing and monochromatic mode printing.
The first feed amount may be equal to mxc3x97D (where m is an integer of 2 or greater that disjoints with k). In such case, it is preferable that the second feed amount is determined such that a sub-scan by the second feed amount will put an upper end nozzle of the achromatic nozzle group at a position of a main scan line immediately below a lower edge of the bundle of main scan lines recorded by the immediately prior unit scan operation without any gap therebetween. It is also preferable that the third feed amount is determined such that a sub-scan by the third feed amount will put a nozzle positioned at the very top of the nozzles of the plurality of single chromatic nozzle groups at a position of a main scan line immediately below a lower edge of a bundle of main scan lines without any gap therebetween for which recording is completed by the immediately prior unit scan operation. In such an embodiment partial interlace printing is executed, so the quality of printing is better.
In a case all conditions described below are fulfilled if the color mode sub-scan and the unit scan operation are performed next, it is preferable that the color mode sub-scan is performed and the unit scan operation is performed, while not forming dots in the monochromatic area by the specific achromatic nozzle group but forming dots in the color area using the single chromatic nozzle groups. The conditions are as follows. (i) A lowermost main scan line of specific achromatic unit lines comes to be positioned within the monochromatic area. The specific achromatic unit lines consists of plural main scan lines for which the specific achromatic nozzle group services with a single unit scan operation. (ii) The uppermost main scan line of color unit lines comes to be positioned within the color area. The color unit lines consists of plural main scan lines for which an uppermost single chromatic nozzle group services with a single unit scan operation.
In a case that all main scan lines of the color unit lines come to be positioned within the monochromatic area when it is assumed that the color mode sub-scan and the unit scan operation are performed next, it is preferable that specific procedure as follows are performed. A sub-scan of a specific feed amount is performed so that the uppermost main scan line of an achromatic unit band comes to an upper edge of the monochromatic area. The achromatic unit band consists of plural main scan lines without any gap therebetween for which the achromatic nozzle group services with a single unit scan operation. The printing procedure proceeds to the monochromatic mode printing. Such an embodiment makes it possible to efficiently execute printing of monochromatic areas when switching from color mode printing to monochromatic mode printing.
In a case that all main scan lines of the color unit lines come to be positioned within the monochromatic area when it is assumed that the color mode sub-scan and the unit scan operation are performed next, the following procedures may be performed. (i) A sub-scan of a specific feed amount is performed so that the uppermost main scan line of an achromatic unit band comes to an upper edge of the monochromatic area. The achromatic unit band consists of plural main scan lines without any gap therebetween for which the achromatic nozzle group services with a single unit scan operation. (ii) The unit scan operation is performed once, while forming dots in the monochromatic area using the achromatic nozzle group. (iii) The printing procedure proceeds to the monochromatic mode printing. Such an embodiment makes it possible to efficiently execute printing of monochromatic areas when switching from color mode printing to monochromatic mode printing.
In color mode printing, as described above, unit scan operations may be performed while dots being formed on the main scan line of the color area using a single chromatic nozzle group, without conducting recording onto the monochromatic area main scan line by a special group of achromatic nozzles. After the unit scan operations, the following may also be done.
In a case that a lowermost main scan line of a color unit band comes to be positioned within the monochromatic area when it is assumed that the color mode sub-scan and the unit scan operation are performed next, specific procedures are preferably performed. The color unit band consists of plural main scan lines without any gap therebetween for which the uppermost single chromatic nozzle group services with a single unit scan operation. The specific procedures are as follows. (i) A sub-scan of a specific feed amount is performed so that the lowermost main scan line of the color unit band comes to a lower edge of the color area when it is assumed that the unit scan operation are performed. (ii) A sub-scan of a specific feed amount is performed so that the uppermost main scan line of an achromatic unit band comes to an upper edge of the monochromatic area, the achromatic unit band consisting of plural main scan lines without any gap therebetween for which the achromatic nozzle group services with a single unit scan operation. (iii) The printing procedure proceeds to the monochromatic mode printing.
In a case that a lowermost main scan line of a color unit band comes to be positioned within the monochromatic area when it is assumed that the color mode sub-scan and the unit scan operation are performed next, specific procedure may be performed. The color unit band consists of plural main scan lines without any gap therebetween for which the uppermost single chromatic nozzle group services with a single unit scan operation. The procedure is as follows. (i) A sub-scan of a specific feed amount is performed so that the lowermost main scan line of the color unit band comes to a lower edge of the color area when it is assumed that the unit scan operation are performed. (ii) The unit scan operation is performed once, while not forming dots in the monochromatic area by the specific achromatic nozzle group but forming dots in the color area using the single chromatic nozzle groups. (iii) A sub-scan of a specific feed amount is performed so that the uppermost main scan line of an achromatic unit band comes to an upper edge of the monochromatic area. The achromatic unit band consists of plural main scan lines without any gap therebetween for which the achromatic nozzle group services with a single unit scan operation. (iv) The unit scan operation is performed once, while forming dots in the monochromatic area using the achromatic nozzle group. (v) The printing procedure proceeds to the monochromatic mode printing. Even in this type of mode, it is possible to efficiently execute printing of the monochromatic area when an attempt is made to transition from color mode printing to monochromatic mode printing.
Furthermore, in color mode printing, when the following conditions are satisfied, assuming that there will next be executed a sub-scan for the color mode, it is preferable that after the color mode sub-scan has been executed, a unit scan operation is executed while dots are being formed on the main scan line of the color area using a single chromatic nozzle group, without any recording onto the monochromatic area main scan line by the special group of achromatic nozzles. The conditions to be satisfied are as follows. (i) A lowermost main scan line of specific achromatic unit lines comes to be positioned within the monochromatic area when it is assumed that the color mode sub-scan and the unit scan operation are performed next. (ii) Main scan line count Lr2 of a remaining color area is equal to or larger than main scan line count L2 of a single chromatic unit band. The remaining color area is an area of the color area comprising main scan lines not yet been recorded. The single chromatic unit band consists of plural main scan lines without any gap therebetween for which a one of the single chromatic nozzle groups services with a single unit scan operation.
In a case that main scan line count Lr2 of the remaining color area is smaller than main scan line count L2 of the single chromatic unit band, it is preferable that the following procedure to be performed. (i) A sub-scan of a specific feed amount is performed so that the lowermost main scan line of a color unit band comes to a lower edge of the remaining color area. (ii) The unit scan operation is performed once, while not forming dots in the monochromatic area by the specific achromatic nozzle group but forming dots in the color area using the single chromatic nozzle groups. (iii) A sub-scan of a specific feed amount is performed so that the uppermost main scan line of a achromatic unit band comes to an upper edge of the monochromatic area. The achromatic unit band consists of plural main scan lines without any gap therebetween for which the achromatic nozzle group services with a single unit scan operation. (iv) The unit scan operation is performed once, while forming dots in the monochromatic area using the achromatic nozzle group. (v) The printing procedure proceeds to the monochromatic mode printing. Such an embodiment makes it possible to execute the transition process from color mode printing to monochromatic mode printing, based on simple decision criteria.
The printing apparatus may comprise a printing head, a main scan drive unit, a sub-scan drive unit and a control unit. The printing head may have a plurality of single chromatic nozzle groups and an achromatic nozzle group. The plurality of single chromatic nozzle groups each may consist of plurality of nozzles that are arranged at nozzle pitch D where D is a pitch of main scan lines. The plurality of single chromatic nozzle groups is configured to eject mutually different chromatic inks. The achromatic nozzle group may be a nozzle group for ejecting achromatic ink and consist of a greater number of nozzles that are arranged at nozzle pitch D than each of the single chromatic nozzle groups. The main scan drive unit may move at least one of the printing head and the printing medium to perform main scanning. The sub-scan drive unit may move at least one of the printing head and the printing medium in a direction that intersects a main scanning direction to perform sub-scanning. The control unit may control each of the printing head, the main scan drive unit and the sub-scan drive unit.
With that printing apparatus, monochromatic mode printing may be executed by repeating a main scan using all the nozzles of the achromatic nozzle group but without using the single chromatic nozzle groups. In the monochromatic mode printing, a monochromatic mode sub-scan of a first feed amount is performed in each interval between each main scans.
With that printing apparatus, color mode printing may be executed by repeating the main scan using a specific achromatic nozzle group and the plurality of single chromatic nozzle groups while a color mode sub-scan of a second feed amount less than the first feed amount is performed in each interval between each main scans. The specific achromatic nozzle group is part of the achromatic nozzle group.
In the monochromatic mode printing, if the conditions are all satisfied, specific procedure is preferably performed. The conditions are as follows. (i) A lowermost nozzle of the achromatic nozzle group comes to be positioned over the color area when it is assumed that the monochromatic mode sub-scan is performed next. (ii) A lowermost nozzle of the specific achromatic nozzle group comes to be positioned over the color area when it is assumed that a sub-scan of a feed amount J times (where J is an integer of two or greater) the second feed amount of the color mode sub-scan is performed. (iii) A lowermost nozzle of the specific achromatic nozzle group comes to be positioned over the monochromatic area when it is assumed that a sub-scan of a feed amount (Jxe2x88x921) times the second feed amount of the color mode sub-scan is performed.
The specific procedure is as follows. (i) A sub-scan of a feed amount (Jxe2x88x921) times the second feed amount of the color mode sub-scan is performed. (ii) The main scan is performed once, while forming dots in the monochromatic area using the achromatic nozzle group. (iii) The printing procedure proceeds to the color mode printing. Such an embodiment makes it possible to efficiently execute monochromatic mode printing when an attempt is made to transition to color mode printing.
In a case that a lowermost nozzle of the specific achromatic nozzle group comes to be positioned over the color area when it is assumed that the color mode sub-scan is performed next, it is preferable that the printing procedure proceeds to the color mode printing. Such an embodiment makes it possible to efficiently transition to color mode printing when the distance from the lower tip of the print head to the color area and boundary is less than a prescribed value, after a main scan has been completed while recording dots in the monochromatic areas.
The sub-scan of a feed amount (Jxe2x88x921) times the second feed amount of the color mode sub-scan may be performed in a case that main scan line count Lr1 of a remaining monochromatic area is (i) smaller than a nozzle number N1 (where N1 is an integer of two or greater) of the achromatic nozzle group, (ii) equal to or larger than a number of (Jxe2x88x921) times (where J is an integer of two or greater) a nozzle number N2 (where N2 is an integer of two or greater) of the specific achromatic nozzle group, and (iii) smaller than a number of J times the nozzle number N2. The main scan then may be performed once, while forming dots in the monochromatic area using the achromatic nozzle group. The printing procedure may proceed to the color mode printing. Such an embodiment makes it possible to execute transition processing from monochromatic mode printing to color mode printing based on simple decision criteria.
In a case that main scan line count Lr1 of the remaining monochromatic area is smaller than the nozzle number N2, it is preferable that the printing procedure proceeds to the color mode printing. Such an embodiment makes it possible to execute transition processing from monochromatic mode printing to color mode printing based on simple decision criteria when the distance from the lower tip of the print head to the color area and boundary is less than a prescribed value, after a main scan has been completed while recording dots in the monochromatic areas.
In case that (i) the plurality of single chromatic nozzle groups includes C nozzle rows, where C is an integer of at least 2, (ii) each of the plurality of single chromatic nozzle groups includes N nozzles, where N is an integer of at least 2, arranged in the sub-scan direction at the nozzle pitch D, and also (iii) the achromatic nozzle group includes a nozzle row consisting of Nxc3x97C nozzles arranged in the sub-scan direction at the nozzle pitch D, then the first feed amount is preferably equal to Nxc3x97Cxc3x97D, and the second feed amount is preferably equal to Nxc3x97D. Such an embodiment makes it possible to efficiently execute printing without gaps, for the monochromatic areas and the color areas respectively.
In a case that when it is assumed that the color mode sub-scan is performed next, (i) a lowermost nozzle of specific achromatic nozzle group comes to be positioned over the monochromatic area, and also (ii) a nozzle positioned at the very top of the nozzles of the plurality of single chromatic nozzle groups comes to be positioned over the color area, the procedures as follows is preferably performed. The color mode sub-scan is performed. The main scan is performed, while not forming dots in the monochromatic area by the specific achromatic nozzle group but forming dots in the color area using the single chromatic nozzle groups.
In a case that all nozzles of the plurality of single chromatic nozzle groups come to be positioned within the monochromatic area when it is assumed that the color mode sub-scan is performed next, the procedures as follows is preferably performed. A sub-scan of a specific feed amount is performed so that an uppermost nozzle of the achromatic nozzle group comes over an upper edge of the monochromatic area. The main scan is performed once, while forming dots in the monochromatic area using the achromatic nozzle group. The printing procedure proceeds to the monochromatic mode printing. Such an embodiment makes it possible to efficiently execute printing of the monochromatic areas when transitioning from color mode printing to monochromatic mode printing.
In color mode printing, as described above, main scans may be performed while dots being formed on the main scan line of the color area using a single chromatic nozzle group, without conducting recording onto the monochromatic area main scan line by a special group of achromatic nozzles. After the main scans, the following may also be done.
In a case that a lowermost nozzle of an uppermost single chromatic nozzle group comes to be positioned within the monochromatic area when it is assumed that the color mode sub-scan is performed next, the procedures as follows may be performed. (i) A sub-scan of a specific feed amount is performed so that the lowermost nozzle of the uppermost single chromatic nozzle group comes to a lower edge of the color area. (ii) The main scan is performed once, while not forming dots in the monochromatic area by the specific achromatic nozzle group but forming dots in the color area using the single chromatic nozzle groups. (iii) A sub-scan of a specific feed amount is performed so that an uppermost nozzle of the achromatic nozzle group comes over an upper edge of the monochromatic area. (iv) The main scan is performed once, while forming dots in the monochromatic area using the achromatic nozzle group. (v) The printing procedure proceeds to the monochromatic mode printing. Such an embodiment makes it possible to efficiently execute monochromatic areas printing when an attempt is made to transition from color mode printing to monochromatic mode printing.
In a case that (i) a lowermost nozzle of specific achromatic nozzle group comes to be positioned over the monochromatic area when it is assumed that the color mode sub-scan is performed next, and (ii) main scan line count Lr2 of a remaining color area is equal to or larger than a nozzle number N2 of the single achromatic nozzle group, the procedures as follows are preferably performed. The remaining color area is an area of the color area comprising main scan lines not yet been recorded. (i) The color mode sub-scan is performed. (ii) The main scan is performed, while not forming dots in the monochromatic area by the specific achromatic nozzle group but forming dots in the color area using the single chromatic nozzle groups.
In a case that main scan line count Lr2 of the remaining color area is smaller than the nozzle number N2 of the single achromatic nozzle group, it is preferable that the procedure as follows are performed. (i) A sub-scan of a specific feed amount is performed so that a lowermost nozzle of an uppermost single chromatic nozzle group comes over a lower edge of the remaining color area. (ii) The main scan is performed once, while not forming dots in the monochromatic area by the specific achromatic nozzle group but forming dots in the color area using the single chromatic nozzle groups. (iii) A sub-scan of a specific feed amount is performed so that the uppermost nozzle of the achromatic nozzle group comes to an upper edge of the monochromatic area. (iv) The main scan is performed once, while forming dots in the monochromatic area using the achromatic nozzle group. (v) The printing procedure proceeds to the monochromatic mode printing. Such an embodiment makes it possible to execute transition processing from color mode printing to monochromatic mode printing based on simple decision criteria.
The present invention can be realized in a variety of embodiments such as those shown below.
(1) Printing method and printing control method
(2) Printing apparatus and printing control apparatus
(3) A computer program for realizing the aforementioned device or method
(4) A recording medium on which is recorded a computer program for realizing the aforementioned device or method
(5) Data signals implemented within carrier waves including a computer program for realizing the aforementioned device or method
These and other objects, features, aspects, and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments with the accompanying drawings.